意外& quot;意外TypeError:XXX不是构造函数"Babel和ES6错误

问题描述：

我正在尝试Webpack，并正在尝试本教程，赠送或接受一些自定义的东西.

I am giving a try to Webpack, and am giving a try to the instructions in this tutorial, give or take a few custom things.

这确实是简单的代码，但是我对此错误感到非常困惑，觉得这是我错过的愚蠢的东西.

This is simple code, really, but I'm quite puzzled about this error, and feel this is something silly that I missed.

我定义了两个ES6类，每个类对应于一个Handlebars模板，并且我的应用程序的入口点应该用它们的内容替换索引文件中的占位符HTML:

I defined two ES6 classes, each corresponding to a Handlebars template, and my app's entrypoint is supposed to replace the placeholder HTML in the index file by their contents:

入口点:

import './bloj.less'

// If we have a link, render the Button component on it
if (document.querySelectorAll('a').length) {
    require.ensure([], () => {
        const Button = require('./Components/Button.js');
        const button = new Button('9gag.com');

        button.render('a');
    }, 'button');
}

// If we have a title, render the Header component on it
if (document.querySelectorAll('h1').length) {
    require.ensure([], () => {
        const Header = require('./Components/Header.js');

        new Header().render('h1');
    }, 'header');
}

索引:

<!DOCTYPE html>
<html>
<head>
</head>
<body>
    <h1>My title</h1>
    <a>Click me</a>

    <script src="build/bloj.js"></script>
</body>
</html>

按钮:

import $ from 'jquery';
import './Button.less';

export default class Button {

    constructor(link) {
        this.link = link;
    }

    onClick(event) {
        event.preventDefault();
        alert(this.link);
    }

    render(node) {
        const text = $(node).text();
        var compiled = require('./Button.hbs');

        // Render our button
        $(node).html(
            compiled({"text": text, "link": this.link})
        );

        // Attach our listeners
        $('.button').click(this.onClick.bind(this));
    }
}

标题:

import $ from 'jquery';
import './Header.less';

export default class Header {
    render(node) {
        const text = $(node).text();
        var compiled = require('./Header.hbs');

        // Render the header
        $(node).html(
            compiled({"text": text})
        );
    }
}

遗憾的是，它不起作用，并且在显示页面时出现以下两个错误:

Sadly, it does not work, and I get both these errors when displaying the page:

Uncaught TypeError: Header is not a constructor
Uncaught TypeError: Button is not a constructor

我可能会缺少什么?

这是我的webpack配置:

Here is my webpack configuration:

var path = require('path');
var webpack = require('webpack');
var CleanPlugin = require('clean-webpack-plugin');
var ExtractPlugin = require('extract-text-webpack-plugin');

var production = process.env.NODE_ENV === 'production';
var appName = 'bloj';
var entryPoint = './src/bloj.js';
var outputDir =  './build/';
var publicDir = './build/';

// ************************************************************************** //

var plugins = [
    //new ExtractPlugin(appName + '.css', {allChunks: true}),
    new CleanPlugin(outputDir),
    new webpack.optimize.CommonsChunkPlugin({
        name:      'main',
        children:  true,
        minChunks: 2
    })
];

if (production) {
    plugins = plugins.concat([
        new webpack.optimize.DedupePlugin(),
        new webpack.optimize.OccurenceOrderPlugin(),
        new webpack.optimize.MinChunkSizePlugin({
            minChunkSize: 51200 // 50ko
        }),
        new webpack.optimize.UglifyJsPlugin({
            mangle:   true,
            compress: {
                warnings: false // Suppress uglification warnings
            }
        }),
        new webpack.DefinePlugin({
            __SERVER__:      false,
            __DEVELOPMENT__: false,
            __DEVTOOLS__:    false,
            'process.env':   {
                BABEL_ENV: JSON.stringify(process.env.NODE_ENV)
            }
        })
    ]);
}

module.exports = {
    entry:  entryPoint,
    output: {
        path:     outputDir,
        filename: appName + '.js',
        chunkFilename: '[name].js',
        publicPath: publicDir
    },
    debug:   !production,
    devtool: production ? false : 'eval',
    module: {
        loaders: [
            {
                test: /\.js/,
                loader: "babel",
                include: path.resolve(__dirname, 'src'),
                query: {
                    presets: ['es2015']
                }
            },
            {
                test: /\.less/,
                //loader: ExtractPlugin.extract('style', 'css!less')
                loader: "style!css!less"
            },
            {
                test:   /\.html/,
                loader: 'html'
            },
            {
                test: /\.hbs/,
                loader: "handlebars-template-loader"
            }
        ]
    },
    plugins: plugins,
    node: {
        fs: "empty" // Avoids Handlebars error messages
    }
};

答

我可能会缺少什么?

What could I be missing?

Babel将默认导出分配给 default 属性.因此，如果使用 require 导入ES6模块，则需要访问 default 属性:

Babel assigns default exports to the default property. So if you use require to import ES6 modules, you need to access the default property:

const Button = require('./Components/Button.js').default;

意外& quot;意外TypeError:XXX不是构造函数"Babel和ES6错误

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